Linking with /THREADS_ENABLE

I am on OpenVMS 7.3-1 and 7.3-2 on Alpha machines. The /THREADS_ENABLE qualifier on the LINK command is documented to affect the image being linked, by setting flags on the image to allow upcalls and multiple kernel threads when the image is executed. I have assumed that the qualifier would be needed only on executable images and that shared images would behave in accordance with whatever executable image was using them. Does anybody know whether I need to link my shared images with that qualifier, too?